So, yes you can get a sore arm from an IV but most of the time it is from trauma to the area or a badly inserted
IV etc. You can get an infection at an
IV site but they do use Betadine Iodine and other antiseptics to clean the area well. Usually, the infection comes from an IV or catheter tip left in for several days or longer. A well known source of infection is by Staphylococcus epidermidis (usually) but there are other organisms that can infect a catheter site.